材料期刊网

以线性聚丙烯(PP)为原材料,经压缩气体膨化处理和电晕极化处理后,使其具有压电效应,并将其应用在振动能量采集器中.结果表明,PP压电驻极体在厚度方向上的弹性模量和机械品质因数(FOM,d33?g33)分别为1.7 MPa和8.4 GPa-1,利用面积为3.14 cm2单层膜进行能量采集,当振子质量为25.6,33.7和57.7 g时,其共振频率分别为2300,2000和1800 Hz,在各自的匹配负载条件下,获得的输出功率分别为10.1,13.2和16.9μW/g2.将两片PP膜电学串联,当振子质量为33.7 g时,在共振频率1400 Hz和匹配负载4.3 MΩ的条件下,可以获得的输出功率为15μW/g2.

Cellular polypropylene (PP)films were rendered piezoelectric after pressed gas expansion treatment and proper polarization,and applied in vibration energy harvesters.The results show that Young's modulus in thickness direction determined from dielectric resonance spectra,and the figure of merit FOM (d33?g33 )are 1.7 MPa and 8.4 GPa-1 ,respectively.For a PP film sample with a quasi-static piezoelectric d33 coefficient of 280 pC/N,area of 3.14 cm2 ,and capacitance of 59 pF at 1000 Hz,a normalized output power of 16.9μW/g2 was obtained under conditions of a seismic mass of 57.7 g,a matched load resistance of 2.4 MΩ,and a resonance frequency of 1800 Hz.Two pieces of PP films were in electrical series,the capacitance is 25.4 pF in total.The output power of 15μW/g2 was obtained with an area of 3.14 cm2 ,a seismic mass of 33.7 g and a matched load resistance of 4.3 MΩ.The piezoelectrets based energy harvesters may be used to power low-power electronics.